include/qemu/osdep.h: Add Emscripten-specific OS dependencies

On emscripten, some implementations in os-posix.c can't be used such as
daemonizing and changing user. This commit introduces os-wasm.c and
os-wasm.h which are forked from os-posix.c and os-posix.h and patched for
targetting Emscripten.

Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
Link: https://lore.kernel.org/r/9fc7b106ecf86675b4532bd6778b7b5945442f89.1745820062.git.ktokunaga.mail@gmail.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 119 insertions, 0 deletions

diff --git a/os-wasm.c b/os-wasm.c
new file mode 100644
index 0000000000..d240c180c5
--- /dev/null
+++ b/os-wasm.c
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * os-wasm.c
+ * Forked from os-posix.c, removing functions not working on Emscripten
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ * Copyright (c) 2010 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include <sys/resource.h>
+#include <sys/wait.h>
+#include <pwd.h>
+#include <grp.h>
+#include <libgen.h>
+
+#include "qemu/error-report.h"
+#include "qemu/log.h"
+#include "system/runstate.h"
+#include "qemu/cutils.h"
+
+void os_setup_post(void){}
+void os_set_line_buffering(void)
+{
+    setvbuf(stdout, NULL, _IOLBF, 0);
+}
+void os_setup_early_signal_handling(void)
+{
+    struct sigaction act;
+    sigfillset(&act.sa_mask);
+    act.sa_flags = 0;
+    act.sa_handler = SIG_IGN;
+    sigaction(SIGPIPE, &act, NULL);
+}
+void os_set_proc_name(const char *s)
+{
+    error_report("Change of process name not supported by your OS");
+    exit(1);
+}
+static void termsig_handler(int signal, siginfo_t *info, void *c)
+{
+    qemu_system_killed(info->si_signo, info->si_pid);
+}
+
+void os_setup_signal_handling(void)
+{
+    struct sigaction act;
+
+    memset(&act, 0, sizeof(act));
+    act.sa_sigaction = termsig_handler;
+    act.sa_flags = SA_SIGINFO;
+    sigaction(SIGINT,  &act, NULL);
+    sigaction(SIGHUP,  &act, NULL);
+    sigaction(SIGTERM, &act, NULL);
+}
+void os_setup_limits(void)
+{
+    struct rlimit nofile;
+
+    if (getrlimit(RLIMIT_NOFILE, &nofile) < 0) {
+        warn_report("unable to query NOFILE limit: %s", strerror(errno));
+        return;
+    }
+
+    if (nofile.rlim_cur == nofile.rlim_max) {
+        return;
+    }
+
+    nofile.rlim_cur = nofile.rlim_max;
+
+    if (setrlimit(RLIMIT_NOFILE, &nofile) < 0) {
+        warn_report("unable to set NOFILE limit: %s", strerror(errno));
+        return;
+    }
+}
+int os_mlock(bool on_fault)
+{
+#ifdef HAVE_MLOCKALL
+    int ret = 0;
+    int flags = MCL_CURRENT | MCL_FUTURE;
+
+    if (on_fault) {
+#ifdef HAVE_MLOCK_ONFAULT
+        flags |= MCL_ONFAULT;
+#else
+        error_report("mlockall: on_fault not supported");
+        return -EINVAL;
+#endif
+    }
+
+    ret = mlockall(flags);
+    if (ret < 0) {
+        error_report("mlockall: %s", strerror(errno));
+    }
+
+    return ret;
+#else
+    (void)on_fault;
+    return -ENOSYS;
+#endif
+}